Rainbow Electronics MAX9729 User Manual
Page 23
capacitor as close to V
DD
as possible. Route PGND
and all traces that carry switching transients away from
SGND and the audio signal path. Route digital signal
traces away from the audio signal path. Make traces
perpendicular to each other when routing digital sig-
nals over or under audio signals.
The thin QFN package features an exposed paddle
that improves thermal efficiency. Ensure that the
exposed paddle is electrically isolated from PGND,
SGND, and V
DD
. Connect the exposed paddle to
SV
SS
when the board layout dictates that the
exposed paddle cannot be left unconnected.
MAX9729
Stereo Headphone Amplifier with BassMax,
Volume Control, and Input Mux
______________________________________________________________________________________
23
C6 (nF)
f
POLE
(Hz)
f
ZERO
(Hz)
100
38
106
82
47
130
68
56
156
56
68
190
47
81
230
22
174
490
10
384
1060
Table 11. BassMax Pole and Zero
Examples for a Gain Boost of 8.8dB
(R1 = 47kΩ, R2 = 22kΩ)
GAIN PROFILE WITH AND
WITHOUT BassMax
FREQUENCY (Hz)
A
V
(dB)
1k
100
10
-8
-6
-4
-2
0
2
4
6
8
10
-10
1
10k
MAX9729
CMD REGISTER
CODE = 0xFF
R1 = 47k
Ω
R2 = 22k
Ω
C3 = 0.1
μF
f
POLE
f
ZERO
WITH
BassMax
WITHOUT
BassMax
Figure 9. BassMax Gain Profile Example